Policemen on guard at Uttar Dalkhola High School on Tuesday. (Nantu Dey)

Raiganj, March 6: A mysterious allergy that affected all 26 Madhyamik examinees in a classroom of a Dalkhola school forced the authorities to start the exam half an hour after the scheduled time.

The examinees, all of them girls, were also given an extra 30 minutes. Three of them wrote the exam, the mathematics paper, from the sick room of the block hospital.

As soon as the examinees entered the classroom at Uttar Dalkhola High School, 45km from here, they started complaining that their arms and legs were itching.

The school authorities immediately summoned doctors from the local health centre. The doctors administered anti-allergic drugs to the affected students. Three of them had to be admitted to the rural hospital at Karandighi, 12km from the centre, which had around 250 examinees.

All the examinees were students of Dalkhola High School.

Rahima Khatun, who was among those hospitalised, said: “At first I thought that I was being bitten by mosquitoes. Soon the others started complaining. Red spots came up on our hands and legs. We began to scream. The teachers on duty then called the doctors.”

Udayan Kundu, one of the doctors who attended to the girls, said it was very difficult to pinpoint the cause of the allergy. “It was possibly airborne and could have been caused by dust-borne mites or some insect. We had given them anti-allergy medicines and three of them, whose skin eruptions were very severe had to be shifted to the hospital,” Dr Kundu said.

The headmaster of the school, Rajendra Prasad Das, said the classrooms were dusted daily.

“We clean the classrooms before each exam and all of them were cleaned this morning as well,” Das said.

The member of the West Bengal Board of Secondary Examination for the district, Bipul Mitra, said that the examination for these 26 girls began at 12.30pm. “The incident is unfortunate and we have allowed the affected examinees an extra 30 minutes to complete the paper. We are also sending a report to our office in Calcutta. There were a total of 250 boys and girls who sat for their examination at the Uttar Dalkhola High School centre,” Mitra said.

In Calcutta, Chaitali Dutta, the president West Bengal Board of Secondary Education, said the students had been given an extra 15 minutes.

“We will conduct an inquiry to find whether the itching was because of an allergy from a particular substance kept there. The students were given 15 extra minutes to answer the paper. Three students were admitted to hospital where they wrote the exam,” said Dutta.